Combined mechanical and electrical reproducer and transmitter



June 5,- 1928. 1,672,063 A. HEWITT COMBINED MECHANICAL AN D ELECTRICAL REPRODUCER AND TRANSMITTER Original Filed Dec. 15, 1924 2 Sheets-Sheet 1 M Z0 3/ A5 June 5, 1928.

1,672,063 A. HEWITT COMBINED MECHANICAL AND ELECTRICAL REPRODUCER AND TRANSMITTER Original Filed Dec. 15, 1924 2 Sheets-Sheet 2 Patented June 5, 1928.

UNITED STATES PATENT OFFICE.

ALBERTIS HEWITT, OF PITMAN, NEW JERSEY, ASSIGNOB TO VICTOR TALKING MACHINE COMPANY, A CORPORATION OF NEW JERSEY.

COMBINED MECHANICAL AND ELECTRICAL BEPRODUCER AND TRANSMITTER Original application filed December 15, 1924, Serial No. 756,571. Divided and this application filed February 19, 1925. Serial No. 10,335.

This invention relates to the reproduction and transmission of sound, and more particularly to means adapted for use in combination with talking machines, or electrical circuits, or both, for reproducing recorded sounds, for converting electrical impulses into sound waves, and for converting sound waves into electrical impulses.

An object of the present invention is to provide an improved sound box or reproducer for mechanically reproducing talking machine records.

Another object of the invention is to provide an improved combination device for either mechanical or electrical reproduction, or both, of talking machine records.

Another object is to provide an improved device capable of performing the above functions, and capable of being used as a magnetic transmitter or microphone.

A further object of the invention is to provide an improved device of the above character which may be employed, in combination with other elements, as a radio loud speaker.

A still further object is to provide novel means capable of producingsuperior results for mounting the stylus bar. These and other objects will be apparent from the following detailed description.

Stated broadly the invention comprises improved means for mechanically reproducing talking machine records, for electrically reproducing talking machine records, for simultaneously reproducing such records mechanically and electrically, and one which is adapted for use as an electrical transmitter or microphone, and as a loud speaker unit for radio receiving systems.

The invention is capable of receiving a variety of mechanical expressions, one of which is illustrated in the accompanying drawings, but it is to be expressly understood that the drawings are for purposes of illustration only and are not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

' In the drawings,

Fig. 1 is a front elevation illustrating one embodiment of the present invention;

Fig. 2 is a sectional side elevation taken on the line 22 of Fig. 1;

Fig. 3 is a longitudinal sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a detail perspective view i lustrating one type of stylus bar which may be employed;

Figs. 5 and 6 are sectional details of the stylus bar and its mounting, Fig. 6 being taken on the line 6-6 of Fig. 5;

Fig. 7 is a diagrammatic view illustrating one manner in which the device of the present invention may be emplo ed for mechanically and electrically repro ucing sound;

Fig. 8 is a side elevation illustrating the device adapted for use as an electrical transmitter or microphone; and

Fig. 9 illustratesdiagrammatically, one manner in which the device may be used as a radio loud speaker.

Referring to the drawings wherein like reference characters refer to like parts throughout the several views, 10 is a shell or casing of any suitable form and material that is bent inwardly at its forward face to form a circular shoulder 11. A cup 12, of any suitable material, such as aluminum, and provided with a central opening 12, is maintained in engagement with shoulder 11. in any desired way, as by means of screws 13. In contact with the inner periphery of the shell 10, is a cylindrical member 14 that is preferably formed of a dielectric, such as vulcanized rubber. Secured to the opposite or rear end of the chamber formed by the member 14, as by means of screws 15, is an annular member or ring 16 provided on the inner face thereof with an inwardly projecting shoulder 16. In engagement with the inner periphery of member lb and bearing against shoulder 1U. is a resilient ring 17, which is preferably formed of rubber, for a purpose to be described hereinafter. Secured to the rear face of mcmiwr 16, as by means of screws 18. is a closure member 19 provided with a central flanged portion or neck 19" surrounding an opening 19".

Any suitable electro-magnetic means may be mounted in the chamber formed by the elements 12, 14 and l!) dtscribed above for converting mechanical vibrations into electrical vibrations. In the form shown, this means comprises a permanent, circular magnet 20 which is divided at one side to provide spaced poles 20 that are located at the opposite sides of the medial plane ofthe ma et. Secured to the inner surface of eac pole 20, as by meansof screws 21, are Usha ed pole ieces 22 which extend radial y inward rom the pole and which are mounted so that the limbs of one pro ject toward the corresponding limbs of the other pole piece. A flattened spool 23, provided at its op osite ends with flanges 23, is positioned etween the limbs of pole pieces 22 and a suitable coil of wire 24 is wound around the spool between its flanges. Extending within the spool 23 and centrally thereof, is a flat plate 25 constituting an armature, which is secured at its upper end in any suitable manner, as by means of brazing, to a horizontally disposed flexible member or wire 26 that is attached at its forward end to a stylus bar 27, the rear end of the flexible rod or wire 26 being fixedly secured to a flexible diaphragm 28 which is resiliently and securely supported by the resilient member 17 previously referred to.

Disk 28 may be formed of any suitable material but preferably mica is employed. The particular shape or form of the disk and the manner in which it is constructed and mounted forms no part of the present invention.

Any suitable means may be employed for mounting the stylus bar in operative relation to the casing 10; The present invention, however, includes a novel mounting which is productive of superior results. In the form shown, a bar 29 extends horizontally across the front face of casing 10 adjacent the lower portion thereof, and is referably formed integral with said casing. ecured in any desired manner to the front face of bar 29, is a knife edge 30 which extends parallel with the axis of the bar 29 and at right angles to the axis of the stylus bar 27. Mounted on the front face of bar 29, in planes parallel to the axis of the stylus bar 27 and equi-distant therefrom, are a pair of T-shaped lugs 31 (see Figs. 1 and 6) which receive and retain in cooperatve position a pair of U-shaped springs 32 which are suitably secured, as by means of brazing, to the opposite sides of the stylus bar 27 in the plane of the knife edge 30. Lugs 31, springs 32, and knife edge 30, are so proportioned that the springs are maintained in flexed condition, as is clearly illustrated in Fig. 5, when the stylus bar is engaged with the knife edge 30 and the springs 32 have their U-shaped ends engaged under the lugs 31. The usual needle or st lus 33 and retaining means 34 are provided at the lower end of the stylus bar.

suitable means are preferably provided for dampening the natural vibrations of the stylus bar and also for preventing whipping of the same. In the form shown, this means comprises a rubber tube 35 which surrounds the stylus bar and extends from the armature 25 outwardly and downwardly to the up er edges of springs 32.

ecured to the cup '12 and extending within the circular magnet 20 are binding posts 36 to which are secured the op osite ends of coil 24. Conductors 37, whic are attached in any convenient manner to the binding posts 36, pass through an opening.

12 in the on 12, to a suitable circuit (Fig. 7) for receiving the electrical impulses generated by vibration of the armature 25.

The neck or flanged portion 19 of the disk 19 constitutes means for securing the combination device to the tone-arm 38 (see Figs. 7 and 9) of a talking machine. This arm 38 may be mounted in any suitable manner adjacent a turn table 39 which is adapted to carry the usual record tablet 40.

As illustrated in Figs. 3 and 8, the device of the present invention is adapted for use as an electrical transmitter or microphone. When so employed, a bushing or sleeve 41 is inserted within the neck 19, and a mouthpiece 42 of any suitable type is removably secured to the bushing 41.

When the device is used as a mechanical reproducer, the rotation of sound record tablet 4O vibrates the stylus 33, stylus bar 27, and diaphragm 28, in a manner well known in the art. The dampening means 35 reduces irregularities of sound and materially assists in the clear reproduction of the sound record 40. If it is desired to employ the device as acombination mechanical and electrical reproducer, the conductors 37 are connected with a suitable electric circuit, such as is illustrated in Fig. 7 for example. The vibrations of the stylus bar are not only imparted to the diaphragm 28 to mechanically reproduce the records, but said vibrations are also effective to vibrate the armature 25, thereby inducing electrical effects or currents of variable E. M. F. in the coil 24 and consequently in the electrical circuit connected with the conductors 37.

When employed as a microphone, the device is supported in any suitable manner and the sounds to be transmitted are directed into the mouthpiece 42 whereupon the vibrations thus imparted to diaphragm 28 result in vibration of the armature 25 and generation of the currents of variable E. M. F. in the coil 22. This current is transferred by the conductors 37, to any suitable electrical circuit.

If it is desired to employ the combination device of the present invention as a radio loud s eaker, the conductors 37 are connected with tie output or plate circuit of a suitable radio receiving system (not shown) and the casing 10 is positioned in operative relation with a suite le horn in a manner such as that diagrammatically illustrated in Fig. 9,

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wherein the casing is mounted on the gooseneck of a talking machine. The variable currents in conductors 37 and consequently in the coil 24, cause the armature 25 to be vibrated. These vibrations. are transmitted by the flexible portion 26 of the stylus bar to the diaphragm 28 and the sound waves so produced are amplified by the horn of the talking machine.

It will thus be seen that there is provided a combination device. capable of producing superior results, which may be employed as an electrical or mechanical reproducer, or both, as an electrical transmitter or microphone, and as a loud speaker. Novel and elicetive means are also provided for mounting the stylus bar. The parts are readily assembled and so constructed that distortion is reduced to a minimum. The device may be quickly changed from association with certain elements, where it is adapted to perform one or more of the above enumerated functions, and operatively connected to other elements to perform the other functions enumerated. While the embodiments of the invention illustrated in the drawings have been described with considerable particularity, it

is to be expressly understood that the invention is not limited thereto, since the same is capable of being embodied or carried out in a variety of ways, some of which will now readily suggest themselves to those skilled in the art, while changes may be made in the details of construction and arrangement without departing from the spirit of the invention. Reference is therefore to be had to the claims hereto appended for phragm. U-shaped springs carried by said bar, means normally flexing said springs for retaining said bar on the knife-edge and yielding means surrounding said bar for dampening the vibrations thereof.

3. A stylus bar mounting comprising, in combination with a casing. a bar on said casing, a pair of T-shaped lugs carried by said bar. a knife-edge carried by the bar intermediate said lugs, a. stylus bar in en-,

gagement' with said knife-edge, and a pair of U-shaped springs carried by said bar and having engagement with said lugs for maintaining said bar in operative position.

4: A stylus bar mounting eomprisiiw. in combination with a casing, a pair of retaining lugs carried by said casing, a hnife-edge carried by said casing, a stylus bar having operative engagement with said knife-edge, and U-shaped springs carried by said bar and having engagement with said lugs for maintaining said bar in operative position.

5. In combination, a casing, a pair of T-shaped lugs carried thereby. a stylus bar. and a pair of U-shaped springs secured to said bar and engaging said lugs for maintaining said bar in operative position.

(i. A stylus bar mounting comprising, in combination with a casing, a knife-edge carried by said casing, a stylus bar having engagement with said knife-edge, U-shaped springs carried by said bar, and means coacting with said springs for retaining said bar on the knife-edge.

7. In combination, a casing, a knife-edge carried thereby, a stylus bar engaging said knife-edge, U-shapcd springs carried by said bar, and means normally flexing said springs for retaining said bar on the knife-edge.

8. In combination, a casing, a stylus bar mounted for oscillation on said easing. U-shaped springs carried by said bar and extending substantially parallel to the plane of the axis of said bar and to the axis of oscillation, and means eo-aeting with said springs for retaining said stylus bar in position.

In testimony whereof I have signed this specification.

ALBERTIS HEWITT.

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